[Pw_forum] Strange integral magnetic moment

胡树军 Shu-jun Hu hushujun at mail.sdu.edu.cn
Wed Nov 28 04:57:17 CET 2007


Dear all,
When i calculate the doped magnetic semiconductor system Fe_2_In_30_O_47, it was
found that the output total magnetic moment is integral, 8.00 Bohr, like:

******************************
!    total energy              = -1743.92699154 Ry
     Harris-Foulkes estimate   = -1743.92699155 Ry
     estimated scf accuracy    <     0.00000542 Ry

     total magnetization       =     8.00 Bohr mag/cell
     absolute magnetization    =     9.21 Bohr mag/cell
******************************

By performing the consequent projwfc.x calculation, we found that the magnetic
moment of Fe ions is not integral, like:

******************************
     Atom #   1: total charge =   6.6980, s, p, d, f =   0.4324  0.0000  6.2657
                 spin up      =   5.1402, s, p, d, f =   0.2145  0.0000  4.9258
                 spin down    =   1.5578, s, p, d, f =   0.2179  0.0000  1.3399
                 polarization =   3.5825, s, p, d, f =  -0.0034  0.0000  3.5859
     Atom #  27: total charge =   6.7373, s, p, d, f =   0.4393  0.0000  6.2980
                 spin up      =   5.1453, s, p, d, f =   0.2158  0.0000  4.9295
                 spin down    =   1.5920, s, p, d, f =   0.2236  0.0000  1.3685
                 polarization =   3.5533, s, p, d, f =  -0.0078  0.0000  3.5611
******************************

Therefore it can be interpreted that the sum of the moment of all ions is
integral. 

However, when we changed the doping site, ex-c functional (PZ to PBE) or chose the
other doping element, the output magnetic is still integral (i.e. total
magnetization = 4.00 Bohr for Co dopants). It's surprising! I don't think it is a
coincidence. It seems that there would be some restricts to force the moment to be
integral. Does anyone know why? Any reply is appreciated.

                                         Shujun


Following is the input file:

**********************input file*******************************
 &CONTROL
                       title = ino ,
                 calculation = 'relax' ,
                restart_mode = 'from_scratch' ,
                  wf_collect = .true. ,
                      outdir = '/home/work/7.05/temp/' ,
                  pseudo_dir = '/home/work/PSEUDOPOTENTIAL/' ,
                      prefix = ino ,
                       nstep = 1000 ,
                          dt = 10 ,
 /
 &SYSTEM
                       ibrav = 1,
                   celldm(1) = 18.35,
                         nat = 79,
                        ntyp = 5,
                     ecutwfc = 30 ,
                        nbnd = 205,
                 occupations = 'tetrahedra' ,
                     degauss = 0.005 ,
                    smearing = 'methfessel-paxton' ,
                       nspin = 2 ,
   starting_magnetization(4) = 0.3,
   starting_magnetization(5) = 0.3,
 /
  &ELECTRONS
            electron_maxstep = 500,
                    conv_thr = 1E-5 ,
                 startingpot = 'atomic' ,
                 startingwfc = 'atomic' ,
                 mixing_mode = 'plain' ,
                 mixing_beta = 0.3 ,
             diagonalization = 'david' ,
              diago_thr_init = 1E-3 ,
 /
&IONS
                ion_dynamics = 'damp' ,
 /
 &CELL
               cell_dynamics = 'damp-pr' ,
 /
ATOMIC_SPECIES
    O   15.99940  O.pz-rrkjus.UPF 
  In1   114.8000  In.pz-bhs.UPF
  In2   114.8000  In.pz-bhs.UPF
  Fe1    55.8470  Fe.pz-nd-rrkjus.UPF
  Fe2    55.8470  Fe.pz-nd-rrkjus.UPF
ATOMIC_POSITIONS alat 
Fe1      0.250000000   0.250000000   0.250000000
In1      0.250000000   0.750000000   0.750000000
In1      0.750000000   0.750000000   0.250000000
In1      0.750000000   0.250000000   0.750000000
In1      0.750000000   0.750000000   0.750000000
In1      0.750000000   0.250000000   0.250000000
In1      0.250000000   0.250000000   0.750000000
In1      0.250000000   0.750000000   0.250000000
In2      0.962352792   0.000000000   0.250000000
In2      0.537647208   0.000000000   0.750000000
In2      0.250000000   0.962352792   0.000000000
In2      0.750000000   0.537647208   0.000000000
In2      0.000000000   0.250000000   0.962352792
In2      0.000000000   0.750000000   0.537647208
In2      0.037647208   0.000000000   0.750000000
In2      0.462352792   0.000000000   0.250000000
In2      0.750000000   0.037647208   0.000000000
In2      0.250000000   0.462352792   0.000000000
In2      0.000000000   0.750000000   0.037647208
In2      0.000000000   0.250000000   0.462352792
In2      0.462352792   0.500000000   0.750000000
In2      0.037647208   0.500000000   0.250000000
In2      0.750000000   0.462352792   0.500000000
In2      0.250000000   0.037647208   0.500000000
In2      0.500000000   0.750000000   0.462352792
In2      0.500000000   0.250000000   0.037647208
Fe2      0.537647208   0.500000000   0.250000000
In2      0.962352792   0.500000000   0.750000000
In2      0.250000000   0.537647208   0.500000000
In2      0.750000000   0.962352792   0.500000000
In2      0.500000000   0.250000000   0.537647208
In2      0.500000000   0.750000000   0.962352792
O        0.390681098   0.155477591   0.382212636
O        0.109318902   0.844522409   0.882212636
O        0.609318902   0.655477591   0.117787364
O        0.890681098   0.344522409   0.617787364
O        0.882212636   0.109318902   0.844522409
O        0.117787364   0.609318902   0.655477591
O        0.617787364   0.890681098   0.344522409
O        0.155477591   0.382212636   0.390681098
O        0.844522409   0.882212636   0.109318902
O        0.655477591   0.117787364   0.609318902
O        0.344522409   0.617787364   0.890681098
O        0.609318902   0.844522409   0.617787364
O        0.890681098   0.155477591   0.117787364
O        0.390681098   0.344522409   0.882212636
O        0.109318902   0.655477591   0.382212636
O        0.617787364   0.609318902   0.844522409
O        0.117787364   0.890681098   0.155477591
O        0.882212636   0.390681098   0.344522409
O        0.382212636   0.109318902   0.655477591
O        0.844522409   0.617787364   0.609318902
O        0.155477591   0.117787364   0.890681098
O        0.344522409   0.882212636   0.390681098
O        0.655477591   0.382212636   0.109318902
O        0.890681098   0.655477591   0.882212636
O        0.609318902   0.344522409   0.382212636
O        0.109318902   0.155477591   0.617787364
O        0.390681098   0.844522409   0.117787364
O        0.882212636   0.890681098   0.655477591
O        0.382212636   0.609318902   0.344522409
O        0.617787364   0.109318902   0.155477591
O        0.117787364   0.390681098   0.844522409
O        0.655477591   0.882212636   0.890681098
O        0.344522409   0.382212636   0.609318902
O        0.155477591   0.617787364   0.109318902
O        0.844522409   0.117787364   0.390681098
O        0.109318902   0.344522409   0.117787364
O        0.390681098   0.655477591   0.617787364
O        0.890681098   0.844522409   0.382212636
O        0.609318902   0.155477591   0.882212636
O        0.117787364   0.109318902   0.344522409
O        0.617787364   0.390681098   0.655477591
O        0.382212636   0.890681098   0.844522409
O        0.882212636   0.609318902   0.155477591
O        0.344522409   0.117787364   0.109318902
O        0.655477591   0.617787364   0.390681098
O        0.844522409   0.382212636   0.890681098
O        0.155477591   0.882212636   0.609318902
K_POINTS automatic 
  2 2 2   1 1 1




------------------------------
Shujun Hu                   e-mail:  hushujun at 163.com
Shandong university         Phone:   +86/0531-88375097
Jinan, Shandong Province, China, 250100


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